Unbalanced splice bar with balanced ratios



Feb. 6, 1940. H. L. LANSING UNBALANCED SPLICE BAR WITH BALANCED RATIOS Filed NOV. ,12, 1938 2 Sheets-Sheet 1 Y Patented Feb. 6, 1940 UNITED "STATES UNBALANCED SPLICE BAR WITH BALANCED RATIOS Horace L. Lansing, Rutherford, N. 1., assignor to a .Poor & Company, New York, N. Y a corpora-.

.tion of Delaware Application November 12,1938, Serial No. 240,153

2 Claims.

This invention relates to that type of splice bars for railway rails of the unsymmetrical and unbalancedtype, that is, of the type having a preponderance of metal in its head to provide 5 top and bottom chords of unequal strength, and its primary object is to provide :1. splice bar of this kind in which there is definitely embodied a proportional distribution of metal in the geometrically unsymmetrical portions of the upper and lower members of the bar to provide analytical symmetry by a balancing of the metal distribution ratios about its middle line,

that is, as to I/S ratio values and S/A ratio values above and below the middle line of the bar.

In the attainment of this object there is produced, according to the present invention, a geometrically unsymmetrical splice bar unbalanced as tohead .and base strength (modulus values) so but balanced as to its said metal distribution ratios about the middle line, the resulting construction better adapting a bar of this type and kind to withstand the strains to which it is sub-' jected in service, while at the same time, efiecting'a very substantial saving in metal and consequently affording a bar which is lighter in weight, and more economical to produce than comparable, known splice bars for use on the same weight and type of railway rail.

It has been discovered by experiment and test that according to the principles of the present invention, as distinguished from the principles and teachings of the Braine Reissue Patents Nos. 16,311 and 16,506, a more eflicient and materially lighter splice bar, unbalanced as to head and.

base strength, may be produced than known bars of the same 'type for the same weight and type of rail. Accordingly, this invention contemplates a geometrically unsymmetrical and unbalanced splice bar section which is substantially balanced as to its metal ratio values above and below'its middle line as distinguished from the prior art, in which this distribution of metal ratio values has been about 'the'neutral axis of the bar. Such a bar, as provided by the present invention, efficiently and effectually resists the strains set up therein, is lighter and therefore less costly than comparable, known splice bars, and not only possesses all requisite base strength, 50 but head strength in excess of its base strength and also in excess of the head strength of comparable, known splice bars, whereby it more efliciently serves its p se than comparable, known splice bars. 55 Foran understanding of the improvements comprising the present invention an understanding 01' the development oi modern splice bars is desirable. Early angle bars possessed decided predominance of strengthin the base due to the use of a heavy base flange. Later, by decreasing 'neutral axis is not feasible. it has. been determined that such a bar may the size of the base flange and by addi'ng a projecting rib on the head, the efficiency of angle bars was materially enhanced, as the modulus values of the top and bottom chords of the bar were made more nearly equal without increasing the weight of the bar. In this connection, greatestefliciency in design in truly balanced bars was attained according to the teachings of Reissue Patents Nos. 16,311 and 16,506, granted to B. G. Braine on August 6, 1926, and December 21, 1926, respectively. According to the teachings of these patents it was possible to obtain analytical symmetry in a geometrically unsymmetrical bar and thereby obtain equality in top and bottom chord modulus values, with consequent high efiiciency, by virtue of equal strength in the head and the base of a bar of minimum weight. VVith-the advent of higher and heavier rails, affording additional fishing space, it became possible to shorten the base flange to an extent to lie entirely .inwardlyof the edge of the rail base and stil maintain adequate stiffness and strength. This development resulted in the well' known toeless bar, respecting which greatest efficiency in design was obtained under the teachings of the Armstrong Patent No. 1,654,397 of December 2'7, 1927, by the balancing, or near balancing, of modulus values of the top and bottom chords of the bar, and an accompanying. balancing ofinertia and ratio values relative to the neutral axis which in this Armstrong patent is coincident with the middle line, which is necessary in a bar balanced according to the teaching of the Armstrong patent. Thus, until the present invention, splice bars had progressed from the early angle bar, stronger in the base, to a balanced bar with equal, or approxi- -mately equal, strength in the head and base.

This latter development would be ideal if the bar were to function as a simple beam. But, in service, rail joint bars are subjected to complex stresses and severe strains, usually to a far greater extent in the head than in the base,

because the top bearing surface of a bar has its load bearing stresses and maximum compressive stresses at its center, where it also is subjected to cutting by the rail ends; whereas, the base bearing surface has only maximum tensile stress at its center. This condition requires that a bar have a preponderance of strength in its head or top member. At the same time, considerationsof economy and efliciency demand that a bar be balanced as to the vI/S and S/A ratios of its top and bottom portions. To provide such a bar by' developing. same about its On the other hand,

practically be produced-bymiddle line development, leaving the neutral axis to fall where-it may in the finished bar. Accordingly, the object of the present invention, more particularly stated, is to provide a splice bar of the toeless type which, while geometrically unsymmetrical in section, is, balanced,- or substantially balanced, as to its US and S/A ratios above and below its middle line, the said middle line in all cases subject to this invention being spaced a definite distance from the neutral axis of the bar; which includes a greater amount of metal in its head than in its base; which is stronger in its head than in its base and also stronger in its head than comparable, known splice bars; which possesses all requisite'base strength, and which, at the same time, is appreciably lighter and therefore less costly than comparable, known splice bars. I v

With the foregoing and other objects in view, which will become more fullyapparent to those skilled in the art as the invention is better understood, the same consists in the novel splice bar construction as will be hereinafter more fully described, illustrated in the accompanying drawings anddefined in the appended claims.

In the accompanying drawings, wherein like characters of reference denote corresponding parts in the different views:!

Figures 1 and 2 are diagrammatic views illus-- trating the method of predetermining the sectional shape of 2. splice jbar embodying the features of the invention;

Figure 3 is a composite view showing a barproduced in accordance with the invention superimposed upon a comparable, known splice bar to illustrate, by contrast, the major differences in a bar constructed in accordance with the invention, over a comparable, known bar.

Figure 4 is asimilar composite view illustrating the invention in the same way in connection with bars adapted for a lighter weight rail than the rail shown in Figure 3.

Figure 5 illustrates a modified form of splice bar made in accordance with the present invention adapted to be used with practically the same 7 height and weight of rail as shown in Figure 3,

and representing a structure of increased inertia and modulus values over the known standard form of bar shown in Figure 3 and at the same time 6.80 lbs. lighter than said standard known form of bar.

In developing the pesent new and advantageous splice bar there are first determined, with reference to a rail which the finished bar is' intended to fit, the boundaries within which the finished'bar must be contained, making due allowance for the clearances which must be observed between the finished bar and the rail, and wheel flanges. In this connection, since the bar is of the toeless type, the outer limit of the base of the. bar is inwardly of the outer edge of the rail flange. On the other hand, joint bolt length and other considerations determine the limit beyond which the outer or bolting face of the web of the bar may not extend, and'enable the definite fixhead and of the base of the ing of the plane of the outer or bolting face of the web with respect to the rail; required clearances of the head and the-base of the bar from the rail web. determine the inner limits of the bar; the required thickness of the web of the bar is known and therefore the inner limit of the web is determined with reference to the outer or bolting face thereof, and rquired wheel flange clearance determines the limit upwardly beyond which the outer portion of the head of the bar may not extend.

As to the outer face of the head .ofthcbar, this w has no limit and its disposition is a result. of

making the head of a width to obtain the desired preponderance of strength therein,'as compared with thebase of the bar.

After the boundaries stated have been established, as indicated by the dotted lines I 0 inFig. 1, and which include inner and outer boundaries for the base of the her, an inner boundary for the head of the bar, and a boundary for wheel flange clearance, a middle line H is established midway between the extreme top and the extreme bottom of said boundaries.

Then, below the middle line H, the boundaryline-en closed area for the base of the bar is, as nearly as practicable, completely blocked into zones l3 extending from the inner to the outer boundary lineslll and of such depths and lengths that corresponding or proportional zones l3 may conveniently be outlined equal distances above the middle line H within the limitations of thel3 are increased in length as compared with the zones l3 by amounts to afford in the head of the bar the desired preponderance in weight and strength in the head as compared with the base. In this way there is obtained what may be termed a "nucleus N of the bar to be produced, which nucleus has proportional amounts of metal spaced equal distances above and below the middle line II and comprising, generally speaking, the major portions of the areas ofthe head and the base of the nucleus.

Following blocking of the top and bottom areas of the nucleus in the manner described, the final, irregular, cross sectional shape of the bar to be produced is outlined around said nucleus as shown in Fig. 2., This results, as is apparent,'in a disproportion of areas in the finished bar outline above and below the middle line of the nucleus, because, in outlining the finished shapes of the head and the base of the bar, more area is required to be added at the bottom of the nucleus than at the top thereof. To correct this, an

area, indicated as H, is removed from the upper,

the nucleus, a small area, designated as II, is removed from the lower, outer portion of the head oi the nucleus. Thus,'the desired proportional distribution of areas above and below the middle line [I are maintained in the finished bar and therefore the finished bar, while geometrically unsymmetrical, is substantially balanced as to its physical property ratios above and below its middle line, or, in other words, is substantially symmetrical analytically and therefore is stronger in its head than in its base. At this point, as a matter of terminology it is of course understood that the physical properties of a joint bar are the moment .of inertia (I), the static moment (8) and area.(A) and that the essence of the present" invention is found in making the ratios of these physical properties in substantial balance or substantial equivalency in the upper and lower halves of the bars. That is, respectively above and below the middle line ofthe bar.

In the present splice bar the middle line and the neutral axis are always spaced 9. distance apart, and by making .use of the balancing of ratios about the middle line, the location of the neutral axis relative to themiddle line for strength of the bar, is automatically determined. The modulus values are computed about the neutral axis, and if no error has been made the top modulus values will exceed the bottom modulus values by the predetermined percentage of diiierence, and no unnecessary amount of metal will be used.

To illustrate: let it be assumed that a bar to be produced in accordance with the invention is 1 1 to have greater strength in its top than in its bottom portion. Immediately the neutral axis will be located. It will lie a distance above the middle line 5% of the distance from the middle line to the extreme topfibre. Then, if the zones 13' are. made longer than the zones l3 and the bar is completed in this manner so that the physical property ratios top and bottom are kept in balance about the middle line, neutral axis calculations will show 10% greater modulus values in the top than in the bottom of the bar.

Froin the calculation figures of the representative bars shown in Figures 3 and 4 of the drawings it will be apparent that the present unbalanced bar, stronger in its head than in its base,

it at least as strong as the nearest comparable prior bar and yet includes a materially lesser amount of metal and therefore is far more economical to produce than comparable, known splice bars. For example, a bar constructed in accordance with the invention to fit a 131 lb. rail is illustrated by A in Fig. 3 and the nearest comparable prior splice bar to fit the same rail is illustratedby B in said Figure 3. s I

\ The new bar A of Figure 3 developed in accordance with'the present invention provides 'a joint having the following physical properties, to wit:

Moment of 'inertia 32.3 Top modulus 12.9 Bottom modulus 12.1 and also the following physical property ratios, to wit: I

Above the middle line:

' I/S- 1.'78 S/A= 1.51 I/A= -2.68

.Below the middle line:

' I/S='1.80 S/A= 1.50 I/A= 2.'l0

The prior known bar B of Figure 3 provides a joint having the following physical properties, to wit: a Moment of inertia 32.2 Top modulus 12.9 Bottom modulus 12.2 and also the following physical property ratios, to wit:

Above the middle line:

I/S=1.64 S/A- 1.38 Below the middle line:

I/S=1.81 S/A=1.54

However, the bar A 'of Figure 3, developed ac- :brdingto the present invention providesa 24" 'joint weighing 31.87 lbs., whereas, the prior bar B of Figure 3 provides a 24" joint weighing 88.40

lbs. Therefore, the said. present bar A is equallyas strong as the prior bar B and represents a 7.4% saving in metal, thus providing a spread in Moment of inertia 23.2 Top modulus -1 10.3 Bottom modulus -1 9.6

and also the following physical property ratios, to wit:

Above the middle line:

US: 1.60 S/A=1.35 I/A=2.16

Below the middle line:

I/S=1.61 S/A=1.35 I/A=2.18

The prior known bar D of Figure 4 provides a joitnt having the following physical properties, to w1 r Moment of inertia 23.6 T01) modulus I 10.3 Bottom modulus 9.9 and also the follo g physical property ratios, I to wit:

Above the middle line:

I/S- =1.51 S/A=1.29

Below the middle line:

I/S=1.64 S/A=1.38

However, the bar C of Figure 4, developed according to the present invention provides a 24" joint weighing 73.17 lbs., whereas, the prior bar D of Figure 4 provides a 24" joint weighing 77.75 lbs. Therefore, the said present bar C is equally as strong 'as the prior bar D and represents a 5.9% saving in metal, thus providing a spread in metal saving which permits the bar 0 to be made even stronger than the prior bar D and still be less in weight.

In short, by constructing a splice bar balanced as to its physical property ratios above and below its middle line and by making said bar stronger in its head than its base, by the method outlined,

there is effected a material saving in metal without sacrifice in strength as compared with near-- est comparable prior splice bars.

Figure 5 illustrates a modified form of splice bar E made in accordance with the present invention adapted to be used with a modified rail of'the same weight as shown in Figure 3 and representing a structure of increased inertia and modulus values over the known standard form of bar shown in Figure 3 and at the same time 6.80 lbs. lighter than said standard known form of bar.

Without further description it is thought that the features and advantages of the invention will be readily apparent to those skilled in the art, and it will of course be understood that changes in the form, proportion and minor details of construction may be resorted to, without departing from the spirit of the invention and scope of the appended claims.

' I claim:

1. A splice bar having, in cross section a materialiy greater area. of metal above than below its middle line and also having its metal distributed' so that the moment of inertia with respect to said middle line is materially greater for the portion of the bar above said middle line than for the portion of the bar below said middle line and the horizontal neutral axis of the bar is disposed materially above said middle line, said bar further having substantially analytical symmetry in that its physical property ratios above and below its middle line are substantially balanced.

2. A splice bar having, in cross section, a materially greater area of inetal above than below its middle line and also having its metal distributed so that the moment of inertia with respect to said middle line is materially greater for the portion of the bar above said middle 'line than for the portion of the bar below said middle line and the horizontal neutral axis of the bar 'is disposed materially above said middle .line, said bar further having substantially analytical symmetry in that its 1/8 and S/A ratios above and below its middle line are substantialLv balanced.

HORACE L. LANSING. 

